Implementation example of uploading and downloading attachments under. net core
- 2021-10-25 06:19:15
- OfStack
This article mainly introduces the uploading and downloading of the following files. Share it with you as follows:
File uploading and downloading is also a common function in the system, not wordy, directly on the code to see the specific implementation.
File upload
. net core receives the file object through IFormFile, and then saves it to the specified place by streaming.
[HttpPost("upload")]
//[DisableRequestSizeLimit] // Disable http Limit size
[RequestSizeLimit(100*1024*1024)] // Limit http Size
public async Task<IActionResult> Post(List<IFormFile> files)
{
try
{
if (files == null || !files.Any())
return AssertNotFound(new ResponseFileResult { Result = false, Code = ResponseCode.InvalidParameters, ErrorMessage = " Attachment cannot be empty " });
string filePath = Path.Combine(Directory.GetCurrentDirectory(), BASEFILE, $@"Template");
if (!Directory.Exists(filePath))
Directory.CreateDirectory(filePath);
var result = new ResponseFileResult();
var fileList = new List<FileResultModel>();
foreach (var file in files)
{
var fileModel = new FileResultModel();
var fileName = ContentDispositionHeaderValue
.Parse(file.ContentDisposition)
.FileName
.Trim('"');
var newName = Guid.NewGuid().ToString() + Path.GetExtension(fileName);
var filefullPath = Path.Combine(filePath, $@"{newName}");
using (FileStream fs = new FileStream(filefullPath, FileMode.Create))//System.IO.File.Create(filefullPath)
{
file.CopyTo(fs);
fs.Flush();
}
fileList.Add(new FileResultModel { Name = fileName, Size = file.Length, Url = $@"/file/download?fileName={newName}" });
}
result.FileResultList = fileList;
return AssertNotFound(result);
}
catch(Exception ex)
{
return AssertNotFound(new ResponseFileResult { Result = false, Code = ResponseCode.UnknownException, ErrorMessage = ex.Message });
}
}
Among them, http will limit the upload file size by default, and http can be disabled by [DisableRequestSizeLimit], or RequestSizeLimit (1024) can be specified to limit the upload size of http.
File download
Compared with uploading, downloading is relatively simple. Find the specified file, convert it into a stream, and return the stream file through the File method provided by. net core to complete the file download:
[HttpGet("download")]
public async Task<IActionResult> Get(string fileName)
{
try
{
var addrUrl = Path.Combine(Directory.GetCurrentDirectory(), BASEFILE, $@"{fileName}");
FileStream fs = new FileStream(addrUrl, FileMode.Open);
return File(fs, "application/vnd.android.package-archive", fileName);
}
catch(Exception ex)
{
return NotFound();
}
}
Summarize